Myriad

Arbitrary code execution server using Docker.
Each language has its own Docker image and so each evaluation will run in the respective language's locked-down container.

Features include:

• Building images on startup.
• Preparing containers on startup or on demand.
• Periodically cleanup running containers.
• Customizable settings for each image:
  • Maximum memory usage.
  • Maximum CPU usage.
  • Maximum evaluation time.
  • Maximum concurrent evaluations.
  • Maximum number of retries.
  • Maximum output size.

Requires Docker 18+ to operate.

Download Pre-Built Binary

Check the Releases tab for pre-built binaries.
The languages folder and an example configuration are also included.

Installation from Source

You can use either stack or cabal.

• stack should be >= 2.1.1, cabal should be >= 2.4.0.0.
• GHC 8.8.3 is required if not already installed by stack or if using cabal.

Make sure the place where stack or cabal places binaries is in your PATH.

• For stack, you can get it with stack path --local-bin.
• For cabal, you should find it in $HOME/.cabal/bin (Linux) or %APPDATA%\cabal\bin (Windows).

Run stack install or cabal new-install inside the project folder.
Or, to build within the project, run stack build or cabal new-build.

Configure and Run

Make sure the configuration is filled out, see config.example.yaml for an example.
Run myriad (or stack run or cabal new-run if you built within the project) to start the server.
The config and languages folder will default to ./config.yaml and ./languages.
You can configure this with --config and --languages.

Endpoints

GET /languages

List of enabled languages.
Example response:

["haskell", "javascript"]

POST /eval

Evaluate code.
JSON payload with language and code keys.
The language is as in the name of a subfolder in the languages directory.
Example payload:

{ "language": "haskell", "code": "main = print (1 + 1)" }

Example response:

{ "result": "2\n" }

Errors with 404 if language is not found, 504 if evaluation timed out, or 500 if evaluation failed for other reasons.

GET /containers

List of containers being handled by Myriad.

POST /cleanup

Kill all containers, giving back the names of the containers killed.